Androgynella nipponicus ( Shiino, 1937 )

Larsen, Kim & Shimomura, Michitaka, 2006, Tanaidacea (Crustacea: Peracarida) from Japan. I. Apseudomorpha from the East China Sea, Seto Inland Sea, and Nansei Islands, Zootaxa 1341, pp. 29-48 : 31-32

Androgynella nipponicus ( Shiino, 1937)

Apseudes nipponicus Shiino, 1937

Material examined

1 female ( NSMT Cru R 245), 1 female ( NSMT Cru R 246), 4 females ( NSMT Cru R 245), 13 females ( NSMT Cru R 245), all from Sagami Bay, depth 13 m. 18 August 1936.

Remarks

Shiino (1937) described Apseudes (now Androgynella Gutu, 2006 ) nipponicus from Sagami Bay. Lang (1953) described A. hermaphroditicus from Antarctica and noted the morphological similarity between his new species and A. nipponicus . Lang considered A. hermaphroditicus separate from A. nipponicus owing to differences in the rostrum, eyelobes and pleonal epimera ( Lang 1953:349). Later, Shiino (1970) found similar­looking specimens from Tierra del Fuego, Argentina. He considered these to be conspecific to those found by Lang and that both species were a form of A. nipponicus and thus stated a bipolar distribution for this species. However, Lang (1958:536) had already synonymized A. hermaphroditicus with A. spectabilis ( Studer, 1883) from the Kerguelen Islands (subantarctic Indian Ocean). It followed that A. nipponicus also must be a synonym of A. spectabilis , as finally stated by Lang (1973), although no direct comparison was ever made between A. nipponicus and A. spectabilis .

As bipolar distributions of non­swimming peracarids are highly unlikely (see Larsen 2005) a closer examination of the type specimens was initiated. Also Gutu (2006:76) found this distribution suspect but refrained from re­erecting A. nipponicus due to lack of morphological evidence. The present study (based on re­examination of the types) reveals that A. nipponicus and A. spectabilis are separate species. The presence of a small but clearly visible ventral spine on the rostrum of A. nipponicus (which is not present in A. spectabilis ), justify the resurrection of A. nipponicus . The eye­lobes and epimera characters mentioned by Lang (1953:349) are less distinct characters and could be attributed to variation or angle of observation. The situation is somewhat complicated by the fact that the material of Shiino’s A. nipponicus forma hermaphroditicus could not be located and the type material of A. hermaphroditicus (SMNH no. 413–421) appears to be lost (K. Sindemark, pers comm.). Judging from Lang’s (1953) illustrations A. hermaphroditicus could very well be a synonym of A. spectabilis as stated by Lang (1958) while A. nipponicus represents a separate species. Examination of the good illustrations of Shiino’s A. nipponicus forma hermaphroditicus ( Shiino 1937:112, figs. 27a, 30f), suggests that the rostrum does not resembles that of A. nipponicus sensu stricto from the type locality, and neither does the shape of the female cheliped carpus. This means that A. nipponicus forma hermaphroditicus and A. hermaphroditicus might well be conspecific and might be conspecific with A. spectabilis , but neither of them is conspecific with the original A. nipponicus . When considering that A. spectabilis has a type locality off Kerguelen Island (Subantarctic), quite remote and different in habitat, to that of A. nipponicus , the distribution patterns also support the separation of these species. The type locality of A. nipponicus forma hermaphroditicus and A. hermaphroditicus is also Antarctic. We thus find sufficient evidence to remove the name A. nipponicus from A. spectabilis and the species A. nipponicus is here re­erected (see also below).